1. Field of the Invention
The present invention relates to a combined processing tool, and particularly, to the tool comprising a skiving unit, a burnishing unit, and a dimple forming unit.
2. Description of the Related Art
Conventionally, a combined processing tool is known for simultaneously performing a cutting and a roller burnishing to an inner surface of a hole of a cut object such as a cylinder. This combined processing tool is provided with a skiving unit for performing the cutting on one side of the tool and provided with a burnishing unit for performing the roller burnishing on the other side; when the tool is moved forward to an inner surface of a workpiece, a cutting edge of the skiving unit cuts the inner surface of the object, and when the tool is moved rearward, rollers of the burnishing unit perform the burnishing. Furthermore, with respect to this kind of combined processing tool, there also exists a type of the tool that performs both of a cutting and a burnishing in moving forward (for example, see Japanese Patent Laid-Open Publication No. 2010-94750).
Furthermore, there exists a combined processing tool for forming dimples on a slide face of a cylinder and the like and forming a burnishing. This kind of combined processing tool performs the burnishing to the slide face, thereby improves a durability and a wear resistance, and forms dimples of an oil pool for improving a lubricity (for example, see Japanese Patent Laid-Open Publication No. 2007-301645).
According to this kind of combined processing tool, when balls and rollers placed in a same retainer contact a convex part of a polygonal mandrel rotating inside the retainer, it is possible to smoothly finish an inner surface of a workpiece through a surface compression action of the rollers with the dimples formed by the balls being thrown outward from the retainer pushed onto the processed surface of the workpiece
However, according to these combined processing tools, when the cutting, the burnishing, and the dimple forming are performed to the inner surface of a workpiece of a cylinder and the like, at least two processes are required; therefore, two kinds of tools used for the processes, respectively, are required, and there exists a problem that not only a manpower and but also cost runs.
Consequently, there is a need for a combined processing tool comprising a skiving unit, a burnishing unit, and a dimple forming unit.